Hydraulic turbine runner



Oct. 7, 1924.

o. c. GOERIZ HYDRAULIC TURBINE RUNNER Origijnal Filed May 27. .92:

1 INVENTOR ATTORNEY I Patented Get. 7, 1924.

UNHTZE. STATES rarest OSCAR C. GOERIZ, OF NEW YORK, N.

v HYDRAULIC TURBINE RUNNER.

Application filed May 27, 1921, Serial No. 473,023. Renewed May 31, 19241.

T all whom it may concern:

Be it known that I,'OsoA1-z C. GOERIZ, a

citizen of the German Republic, and a resi- Hydraulic Turbine Runners, of which the smaller gate opening.

following is a specification.

This invention relates to high speed turbine runners and hasfor its primary object to provide a runner, in which the skin friction is reduced to a minimum, in which the residual loss is likewise reduced, and in which there is more certainty regarding the course of the flow linesall with the purpose in View to produce a most efiicient high speed runner.

In the operation of various types of turbine runners known to the prior art, such for instance as high speed Francis turbine runners, it is a well known fact that, owing to the very considerable vertical extension of the runner blades in the direction of the axis, the water exerts a great leverage against the runner blades over an area of said blades extending between oppositely disposed horizontal planes passing through the upper end and the lower end of said blades.

The pressure against such extended area of those blades under certain heads may become so great as to produce bending strains or stresses tending to break the connection between the blades and the hub upon which they are mounted.

l/Vith this form of runner blade, moreover, there is a considerable change or deviation in the flow line of the water through the runner. Thus, fora large gate opening the flow line varies from the flow line for a Owing to these changes and variations in the flow line of the water course there is an appreciable loss in operating efficiency.

The present improvement is devised with a view to overcoming these disadvantages and to this end, in one embodiment of the invention I provide longitudinally curved runner blades substantially free from vertical extension extending in radial direction between the hub and rim and having curved entrance and exit edges. Thus the rotative surface determined by the curved exit edge is materially more eflicient than in the old type of turbine runner, while owing to the additional fact that the entrance edge of the blade is also curved, the wetted surface thereof is shortened or reduced, a matter of prime consideration in high speed turbines. 1 I

With the above and other objects in vieW, the invention consists in the improved form, construction and relative-arrangement of the several parts as will be hereinafter. more fully described, illustrated in the accompanying drawing and subsequently incorporated in the subjoined claims. I

In the drawing wherein I have illustrated practical embodiments of my present improvement, V

Figure 1. is a View showing one embodiment of my present invention, and

Figure 2 is a View similarto Figure l illustrating another construction and also showing a means for partially counterbalancing the axial thrust upon the runner.

As shown in Figure 1 of the drawing, being one embodiment ofthe present invention, I provide rumier blades 9 which are substantially free from vertical extension extend radially between the hub 6and the rim 8, and are longitudinally curved.

It may be noted that the rim 8 maybe omitted when the individual blades or vanes are made strong enough to withstand all the forces acting upon the same, without showing undue sag or deformation. This statement applies principally to cast steel, cast iron or bronze runners, having no external rim 8, reminding one of ship propellers, but with the distinguishing feature that the arms or blades are curved as described. 7

The curved exit edge 10; of the runner blade affords a much larger rotative surface than the plane exit edge of the previously known axial flow runners and propellers. In high speed runners it is desirable to reducethe wetted surface of the blades as much as possible, consistent with good de sign, and, therefore, the entrance edge 11 of the runner blade is likewise curved. The point of greatest depression of this entrance edge 11 at E, intermediate of the ends A-C of said entrance edge, must be sufficiently low that a straight line connecting the ends B--D of the exit edge 10 of the blade will be tangential to the entrance edge at the point E. In the alternative form of the runner seen in Figure 2, the point of greatest depression E of the entrance edge may be below the line B-D so that said line intersects the entrance edge of the blade at the spaced points L-M. The rotative surface defined by the curved exit edge B, F, D of the blade may, within certain limits, be varied by variations in the length and curvature of the runner blade. in general, the angle B, G, H, between the line BD and the runner axis G-H should amount to about 90 degrees, but it has been ascertained in practice that a variation of 25 degrees either above or below a 90 degree angle may still give favorable conditions so that the said angle of intersect-ion may vary between extreme limits of 65 and 115 degrees.

In Figure 2 of the drawing, a vertically inclined extension 12 is rigidly connected to the hub 6 of the runner and revolves therewith. This hub is provided for the purpose of counterbalancing a part of the axial thrust. To this end the chamber 13 of which the part 12 forms the lower wall above the runner hub is connected by the pipe 14 with either the draft tube of the turbine or directly with the tail water. The counterbalancing effect is principally obtained by the pressure differences above and below the hub extension 12. To some extent such counterbalancing efiect is assisted by the deflection of the water along the curved surface of this hub extension.

It is evident that from considerations of convenience of the production of such turbine runners, the exit edge B, F, D, can be disposed in a horizontal radial plane at least for the greater part of the length of the runner blade. By developing the curves for the blades between the points i'h-B, E F, and C D, a certain harmonious entrance edge A, E, C is generated. @n the other hand, if the curved entrance edge A, E, G appears in the plan view of the runner as an approximately straight radial line, it is manifest that the curved exit edge of the blade, B, F, D, need not necessarily also extend in a radial line with respect to the center of the runner.

From the foregoing description considered in connection with the accompanying drawin s, the construction and several ad vantages of the present invention will be clearly understood. By means of my improved form of runner blade for high speed runners a considerable improvement of efficiency is obtained.

While 1 have herein shown and described several practical constructions of the invention, it will nevertheless be understood that the same is also susceptible to still further modifications in the form proportion and arrangement of its several parts and I, therefore, reserve the privilege of resorting to all such legitimate changes as may be fairly embodied within the spirit and scope of the invention as claimed.

1 claim:

1. A turbine runner comprising a hub and blades extending laterally therefrom and provided with longitudinally curved entrance .and exit edges, the point ofgreatest depression of the entrance edge being disposed approximately in .a horizontal plane extending through the ends of the exit edge of the runner blades at a rig-ht angle to the axis of said hub.

2. A turbine runner comprising a hub and blades extending laterally therefrom and provided with longitudinally curved entrance and exit edges, and a rim connecting the ends of said blades, and the outer edge of said blades lying between two horizontal planes extending at right angles to the axis of said runner, the horizontal medial line between said planes intersecting the inner end of said blades.

3. A. turbine runner comprising a hub and blades extending laterally therefrom and provided with longitudinally curved entrance and exit edges, and a rim connecting the ends of said blades, and the outer edge of said blades lying between two horizontal planes extending at right angles to the axis of said runner, the upper of said planes intersecting the inner end .of said runners.

4. A turbine runner comprising a hub, blades extending laterally therefrom and provided with longitudinally curved entrance and exit edges, and a rim connecting the ends of said blades, and the .outer edge of said blades lying between two horizontal planes extending at rightangles to the axis of said runner, the horizontal medial line between said planes lying above the point of deepest depression of the entrance edge.

In testimony that I claim the foregoing as my invention, and l have signed mv name hereunder.

OS CAR C. GOERlZ i. 

